This invention relates to abrasive articles having projections attached to a major surface thereof, and methods for making such articles. The articles include (1) a reaction product of components that include (a) an epoxy-functional material, (b) at least one of a cyclic anhydride or a diacid derived therefrom; and/or (2) a polymeric material preparable by combining at least (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom.
Conventional coated abrasive articles include a backing having a plurality of abrasive particles bonded to at least one major surface thereof by one or more binders (e.g., make, size, and supersize coats). Abrasive articles (e.g., structured abrasive articles) are preferably formed from a slurry, and include a backing bearing on at least one major surface thereof an abrasive layer including a plurality of abrasive particles dispersed in a binder. For a structured abrasive article, the abrasive layer is in the form of a plurality of shaped abrasive composites bonded to a backing. Useful backings include, for example, paper, polymeric film, vulcanized fiber, nonwoven substrates, and cloth. Cloth backings are generally either stitchbonded or woven. These backings are often treated with treatment coat(s) to seal the cloth and to protect the individual fibers. Structured abrasive articles are disclosed, for example, in U.S. Pat. No. 5,152,917 (Pieper et al.); U.S. Pat. No. 5,681,217 (Hoopman et al.); and U.S. Pat. No. 5,855,652 (Stoetzel et al.).
Certain known structured abrasive articles are capable of working well in a number of finishing and grinding operations. However, there is always potential for improved performance. Areas where improved performance would be particularly useful is in wet grinding and finishing operations and in coarser grade products where higher stock removal rates and longer abrasive lives would be beneficial.
In one aspect, the present invention provides an abrasive article including a backing having a major surface; a plurality of projections attached to the major surface; and a binder including a reaction product of components including (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom. Preferably, the components further include (c) a polyfunctional (meth)acrylate. Optionally, the binder further includes a plurality of abrasive grits. Preferably, the projections are composite projections including abrasive grits. Preferably the binder is present in the backing, on the backing, or in the projections.
In another aspect, the present invention provides an abrasive article including a backing having a major surface; a plurality of projections attached to the major surface; and a binder preparable by combining at least (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom. Preferably, the binder is preparable by combining at least (a) an epoxy-functional material, (b) at least one of a cyclic anhydride or a diacid derived therefrom, and (c) a polyfunctional (meth)acrylate. Optionally, the binder further includes a plurality of abrasive grits. Preferably, the projections are composite projections including abrasive grits. Preferably, the binder is present in the backing, on the backing, or in the projections.
In another aspect, the present invention provides a method of making an abrasive article including providing a production tool having a three-dimensional body with one or more cavities, at least a portion of the one or more cavities having therein a composition preparable by combining at least (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom, and the production tool having a backing that has a major surface adjacent the one or more cavities; and at least partially curing at least a portion of the composition to form an abrasive article. Preferably, the composition is preparable by combining at least (a) an epoxy-functional material, (b) at least one of a cyclic anhydride or a diacid derived therefrom, and (c) a polyfunctional (meth)acrylate. Optionally, providing the production tool further includes providing an intermediate layer between the major surface of the backing and at least a portion of the one or more cavities. Preferably, the method includes irradiating at least a portion of the composition. Preferably, the method includes thermally curing at least a portion of the abrasive article.
In one embodiment, the method of making an abrasive article includes providing a production tool having a three-dimensional body with one or more cavities, at least a portion of the one or more cavities having therein a composition preparable by combining at least (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom; and applying a major surface of a backing to at least a portion of the one or more cavities. Preferably, the composition is allowed to wet the major surface of the backing.
In another embodiment, the method of making an abrasive article includes providing a production tool having a three-dimensional body with one or more cavities; and applying to at least a portion of the one or more cavities a major surface of a backing having thereon a composition preparable by combining at least (a) an epoxy-functional material, and (b) at least one of a cyclic anhydride or a diacid derived therefrom.
The present invention provides a method of making abrasive articles. For some embodiments of the method, abrasive articles are made which preferably provide one or more of the following properties: superior wet grinding performance, superior stock removal rates, and superior abrasive life.
As used herein, xe2x80x9cbinder precursorxe2x80x9d means any material that is conformable or can be made to be conformable by heat or pressure or both and that can be rendered non-conformable by means of radiation energy or thermal energy or both. A binder precursor may include the polymeric material according to the present invention and optional materials including abrasive grits, fillers, and grinding aids.
As used herein, xe2x80x9cbinderxe2x80x9d refers to a solidified, handleable material. Preferably, the binder is formed from reaction of a binder precursor to provide a material (e.g., particles) that will not substantially flow or experience a substantial change in shape. The expression xe2x80x9cbinderxe2x80x9d does not require that the binder precursor is fully reacted (e.g., polymerized or cured), only that it is sufficiently reacted, for example, to allow removal thereof from the production tool while the production tool continues to move, without leading to substantial change in shape of the binder.
It should be understood that where incorporation of an ingredient is specified, either a single ingredient or a combination or mixture of materials may be used as desired. Similarly, articles including xe2x80x9ca,xe2x80x9d xe2x80x9can,xe2x80x9d and, xe2x80x9cthexe2x80x9d are meant to be interpreted as referring to the singular as well as the plural. It should also be understood that the specification of a value that includes the term xe2x80x9caboutxe2x80x9d is meant to include both higher and lower values reasonably close to the specified value. For example, for some properties values either 10% above or 10% below the specified value are intended to be included by use of the term xe2x80x9caboutxe2x80x9d.